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Focusing on Vascular Tone and Breathing Regulations Georgia State University ScholarWorks @ Georgia State University Biology Dissertations Department of Biology 5-9-2016 Insight Into Autonomic Dysfunctions With Novel Interventions: Focusing On Vascular Tone And Breathing Regulations Shuang Zhang Follow this and additional works at: https://scholarworks.gsu.edu/biology_diss Recommended Citation Zhang, Shuang, "Insight Into Autonomic Dysfunctions With Novel Interventions: Focusing On Vascular Tone And Breathing Regulations." Dissertation, Georgia State University, 2016. https://scholarworks.gsu.edu/biology_diss/164 This Dissertation is brought to you for free and open access by the Department of Biology at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Biology Dissertations by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact [email protected]. INSIGHT INTO AUTONOMIC DYSFUNCTIONS WITH NOVEL INTERVENTIONS: FOCUSING ON VASCULAR TONE AND BREATHING REGULATIONS by SHUANG ZHANG Under the Direction of Chun Jiang, PhD ABSTRACT The autonomic nervous system (ANS) controls most involuntary functions of the body. Dysfunctions of the ANS can be life-threatening. However, several critical questions related to cardiovascular and breathing regulations remain unclear. One of the open questions is how the system lose control of the vascular tones under certain circumstances. Using the septic shock model induced by lipopolysaccharide (LPS) in isolated and perfused mesenteric arterial rings, we found the vascular hyporeactivity is attributed to the decreased vasoconstriction to α-adrenoceptor agonists. The endotoxin-induced vasodilation can be intervened with endothelin-1 (ET-1), serotonin (5-HT) or vasopressin, which have never been used in clinical treatment. It is unclear how the excitability of endothelium affects vascular tones. Using optogenetics and transgenic mice with channelrhodopsin expression in endothelial cells (ECs), we found selective activation of the ECs induces a fast, robust, reproducible and long-lasting vasoconstriction in isolated and perfused hearts and kidneys. Breathing control by the ANS within the brain becomes abnormal in certain genetic diseases, such as Rett syndrome with defected norepinephrine (NE) system in locus coeruleus (LC). The LC neurons are hyperexcitable while NE release is deficient. Using optogenetics and double transgenic mice with Mecp2 null and channelrhodopsin expression in LC neurons, we found the NE-ergic modulation of hypoglossal neurons was impaired in transgenic mice, which cannot be improved with optostimulation, suggesting that LC neuronal hyperexcitability may not benefit the NE modulation in Rett syndrome. Collectively, our results provide insight into the autonomic dysfunctions using experimental interventions that have barely been used before. INDEX WORDS: Autonomic nervous system, Dysfunction, Vascular tones, Breathing, Septic shock, Lipopolysaccharide, Endothelium, Optogenetics, Transgenic mice, Rett syndrome INSIGHT INTO AUTONOMIC DYSFUNCTIONS WITH NOVEL INTERVENTIONS: FOCUSING ON VASCULAR TONE AND BREATHING REGULATIONS by SHUANG ZHANG A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the College of Arts and Sciences Georgia State University 2016 Copyright by Shuang Zhang 2016 INSIGHT INTO AUTONOMIC DYSFUNCTIONS WITH NOVEL INTERVENTIONS: FOCUSING ON VASCULAR TONE AND BREATHING REGULATIONS by SHUANG ZHANG Committee Chair: Chun Jiang Committee: Didier Merlin Bingzhong Xue Electronic Version Approved: Office of Graduate Studies College of Arts and Sciences Georgia State University May 2016 iv DEDICATION To my parents Shengguo Zhang and Hui Zhao, who has always been there for me and showed me how to persevere through all of the life’s trails. All I have and will accomplish are only possible due to their love and sacrifices. To my aunt Xingfang Zhao A lovely woman has been very supportive in my educational pursuits. v ACKNOWLEDGEMENTS First and foremost, I would like to thank my advisor, Dr. Chun Jiang. Dr. Jiang is my research advisor and my mentor, who has been motivating, supporting and pushing me to become a better scientist. Without his expert guidance and help, I would not be where I am today. Secondly, I would like to thank all of my committee members, Dr. Bingzhong Xue, Dr. Didier Merlin, Dr. Andrew Clancy, and Dr. Deborah Baro for their valuable suggestions and advice has helped me to conduct better research and improved my dissertation. I would also like to thank other faculty members at GSU. Thanks to Dr. Ritu Aneja, and Dr. Julia Hilliard for their help when I took the qualifying examination. Dr. Blaustein and Nancy Russell, Dr. Matthew Brewer and Stephanie Gutzler for providing wonderful student teaching experience. Thank you, Dr. Phang Tai and Dr. Yi Pan for their suggestion on my academic development. I also thank the staff at GSU. LaTesha Warren provided professional assistance and guidance. Barry Grant for his help with maintenance and repairs. Debby Walthall, Sonja Young, Ping Jiang, Gemia Cameron have been helpful to access research facilities. Tameka Hudson, Stephanie Lewis, Tamara Gross, and Karon Mackey-Conyers for their help with program issues. Department of animal resources staff for their assistance and advice for training and maintaining of experimental animals. Thank you to the many friends and colleagues I have made in GSU, including but not limited to Dr. Yan Li, Johnny Garretson, Dr. Lei Zhong, Dr. Stephen Estes, Dr. Liana Artinian, Maksim Kvetny. Lab members, Dr. Weiwei Shi, Dr. Yang Yang, Casey Trower, Dr. Ningren vi Cui, Dr. Max Oginsky, Dr. Xin Jin, Dr. Xiaotao Jin, Dr. Shanshan Li, Christopher M. Johnson, Dawn Wu, Vivian Zhong, Hao Xing. I acknowledge Molecular Basis of Disease (MBD) Fellowship program for their financial support for my study and research. vii TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................. v LIST OF TABLES .......................................................................................................... xii LIST OF FIGURES ....................................................................................................... xiii LIST OF ABBREVIATIONS ........................................................................................ xv 1 SPECIFIC AIMS AND HYPOTHESES .................................................................. 1 2 INTRODUCTION ...................................................................................................... 3 2.1 Autonomic nervous system ................................................................................. 3 2.1.1 Overview and anatomy of the autonomic nervous system ............................. 3 2.1.2 Function and regulation of the ANS .............................................................. 5 2.1.3 Neural control of the cardiovascular and respiratory systems ...................... 9 2.2 Regulation of vascular tone .............................................................................. 10 2.2.1 Anatomy and physiology of the vasculature ................................................ 10 2.2.2 Function and dysfunction of the vascular smooth muscle .......................... 12 2.2.3 Function and dysfunction of the vascular endothelium.............................. 16 2.2.4 Disorder of vascular tones in multiple cardiovascular diseases ................. 22 2.2.5 Intervention to vasculature: from tradition to optogenetics ........................ 24 2.2.6 Animal models and transgenic mice ............................................................ 31 2.3 Regulation of cardiac function in ANS ............................................................ 33 2.3.1 Anatomy and physiology of the Cardiac Muscle ......................................... 33 viii 2.3.2 Cardiac function and the neural control ..................................................... 34 2.3.3 Coronary circulation and regulation ........................................................... 38 2.3.4 Disorder and intervention of the cardiac function ...................................... 40 2.4 Regulation of respiration .................................................................................. 41 2.4.1 Anatomy and Physiology of Respiratory System ......................................... 41 2.4.2 Regulation of Respiration ............................................................................. 42 2.4.3 Chemosensitive NE-ergic neurons in the LC............................................... 48 2.4.4 Mecp2 and Rett Syndrome ............................................................................ 51 2.4.5 Intervention of neuronal activities ............................................................... 52 3 SIGNIFICANCE ....................................................................................................... 52 4 EXPERIMENTs........................................................................................................ 55 4.1 Animals ............................................................................................................... 55 4.1.1 Rats ................................................................................................................ 55 4.1.2 Mice ............................................................................................................... 55 4.2 Mesenteric arterial septic shock model preparation .....................................
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